1. Field of the Invention
The invention generally relates to methods and apparatus for fixing a pipeline to a coupling. More particularly, the invention relates to methods and apparatus for fixing a pipeline to an internal-thread coupling, utilizing fixing means furnished with slidable external-thread connections on either side.
2. Brief Description of the Related Art
Brake hoses, used in the process of assembling by automotive vehicles, are typically furnished with couplings at the free end of the hoses. These hoses are sometimes fixed to the body and connected to the brake piping before installation of the axles. In most cases, the brakes are provided with internal-thread connections and coupled to the axles. Presently, in order to couple the brake hoses to the brakes upon installation of the axles, pipelines are used which are furnished with at least one slidable external-thread connection being turnable on the pipeline. The pipelines are usually supplied together with the brake hoses as a pre-assembled unit. A number of well known methods and apparatus can be used to fabricate the pre-assembly.
One such method (and associated apparatus) involves soldering the pipelines into the couplings. This can, however, only be done on special machines and must be done before fixing the hose to the coupling since the hose cannot withstand the soldering temperatures without damage. The cost of the soldering method can be prohibitive as well, since when fixing the hoses a large, bulky and often curved part has to be held in place.
Another prior art method involves shearing the pipelines into the couplings. This method also involves the use of expensive special machinery.
Yet another known method for fabricating the pre-assembly, is to provide the pipeline with two slidable, turnable external-thread connections and to provide the coupling with an internal-thread. This is simple and allows the aforementioned fabrication to be carried out at relatively low cost. However, in the state of the art implementation of this last method, both the internal-thread coupling and the two external-thread connections are equipped with external hexagons. As a result, it is possible that the connection between the internal-thread coupling and the pipeline can, through error (such as faulty handling) become detached.
Accordingly, it would be desirable to provide fixing means and methods which improve upon the known methods (and associated apparatus) for fabricating the pre-assembly, so that the fixing of a pipeline to a coupling cannot become detached through error. Furthermore, it would be desirable if the improved fixing methods and apparatus were simple, inexpensive, and automation compatible.